Jimmie Johnson Bungee Jimmie Johnson Bungee JumpingJumping

Alex FalkAlex Falk

Mallory FarrarMallory Farrar

Karen LauKaren Lau

(1:23.7 Scale Model)(1:23.7 Scale Model)

PurposePurpose

Simulate a bungee Simulate a bungee jump by racing star jump by racing star Jimmie JohnsonJimmie Johnson

OverviewOverview

Our device is a 1:23.7 scale model of Jimmie Johnson bungee Our device is a 1:23.7 scale model of Jimmie Johnson bungee jumping a real-life distance of 15.8 feet. A main inspiration for jumping a real-life distance of 15.8 feet. A main inspiration for device components came from a pinball machine “plunger”. A device components came from a pinball machine “plunger”. A desire to make a sturdy and portable device led to the decision to desire to make a sturdy and portable device led to the decision to mount all components on a relatively small piece of MDF board.mount all components on a relatively small piece of MDF board.

Work to Potential Elastic Work to Potential Elastic EnergyEnergy

1.1. Work Input is transferred into Work Input is transferred into a spring by pulling back on a a spring by pulling back on a bolt which is part of a “pinball bolt which is part of a “pinball plunger” device. Maximum plunger” device. Maximum compression is achieved with compression is achieved with a force of 31.5 lbs over a a force of 31.5 lbs over a distance of 1.5 inches. A distance of 1.5 inches. A value of 504 lbs per foot was value of 504 lbs per foot was calculated for the spring calculated for the spring constant K of the spring in the constant K of the spring in the plunger device.plunger device.

Potential Elastic to Kinetic Potential Elastic to Kinetic Energy… and two CollisionsEnergy… and two Collisions

2. When the plunger is released, it strikes a plastic paddle which 2. When the plunger is released, it strikes a plastic paddle which then rotates around a central bolt. On the opposite end of the then rotates around a central bolt. On the opposite end of the paddle, a wooden bumper collides with a golf ball placed at rest at paddle, a wooden bumper collides with a golf ball placed at rest at the top of a ramp. Observation of the device reveals that by this the top of a ramp. Observation of the device reveals that by this point, much of the initial input energy has been lost. This is due point, much of the initial input energy has been lost. This is due to friction occurring in both the plunger device and the paddle. to friction occurring in both the plunger device and the paddle. The collision with the bumper gives the golf ball a approximate The collision with the bumper gives the golf ball a approximate initial horizontal velocity of 2 feet per second.initial horizontal velocity of 2 feet per second.

Gravitational Potential Energy, Gravitational Potential Energy, another Collisionanother Collision

3. The normal force on the 3. The normal force on the ball along the angle of the ball along the angle of the ramp provides extra ramp provides extra acceleration as the ball acceleration as the ball travels towards the travels towards the bottom of the ramp, bottom of the ramp, colliding with our model of colliding with our model of Jimmie Johnson at Jimmie Johnson at approximately 2.9 feet approximately 2.9 feet per second.per second.

Equilibrium of Gravitational Equilibrium of Gravitational and Elastic Potential Energiesand Elastic Potential Energies

4. The figure falls off the side of the board, but the elastic cord prevents 4. The figure falls off the side of the board, but the elastic cord prevents Jimmie from hitting the floor. The system of the figure and the Jimmie from hitting the floor. The system of the figure and the elastic cord reaches equilibrium with Jimmie at a distance of 7 elastic cord reaches equilibrium with Jimmie at a distance of 7 inches below the edge of the board.inches below the edge of the board.

ConclusionsConclusions

Problems in design such as “run-away” Problems in design such as “run-away” golf balls and insufficient golf ball velocity golf balls and insufficient golf ball velocity were corrected with scrap materials (the were corrected with scrap materials (the golf ball ramp and barrier, respectively)golf ball ramp and barrier, respectively)

Jimmie Johnson successfully “bungee Jimmie Johnson successfully “bungee jumps” in a majority of test runsjumps” in a majority of test runs